Draught beverages such as lager and bitter beers, cider and stout are served in bars using pressurized systems. The beverage is supplied to the bar in kegs and is pressurized with carbon dioxide or a mixture of carbon dioxide and nitrogen. This “top pressure” may be up to 2.81 kg cm−2 (40 p.s.i.) in the case of lager beers. The latest approach to dispensing such beverages has a requirement for even higher top pressures. In order to maintain the pressure in the keg at an approximately constant level, carbon dioxide and optionally nitrogen is pumped into the keg as the beverage is supplied to the consumer. If the pressure in the keg dropped, carbon dioxide would be allowed to escape from the beverage during storage, creating foaming or fobbing of the beverage, which is undesirable. The additional carbon dioxide is supplied from bottles that are attached to the bar's dispensing system.
Kegs that have been emptied of liquid (and are hence full of pressurized gas) are returned to the brewery from the bar, where they are vented to atmosphere before being re-filled with beverage. This venting constitutes a significant source of carbon dioxide emissions, and as CO2 is a “greenhouse” gas it is therefore desirable to reduce the amount of these emissions to a minimum. In addition, in order to fill the kegs with carbon dioxide, the bar must regularly purchase or lease bottles of CO2, which are expensive. There is also in environmental impact from the supply of the bottles to different bars, as there are exhaust emissions from the delivery trucks.
It is an object of the present invention to obviate or mitigate these disadvantages with prior art systems, and to provide a gas reclamation system to lessen the need for supplying large quantities of carbon dioxide to run beverage dispensing systems in bars.